Fact-sheet: Shy-Drager syndrome - Multiple system atrophy
Updated on 10/06/2017 at 4:20 PM
View all RADEOS cases associated with this fact-sheet
Definition
Multiple system atrophy (MSA) is a rare sporadic degenerative disease (2 to 5 cases per 100,000 population). It is, however, the most common atypical parkinsonian syndrome along with progressive supranuclear palsy (PSP)
Clinical features
Variable combination of a poorly dopa-responsive parkinsonian syndrome, cerebellar syndrome, and dysautonomia (cardiovascular and vesicosphincteric).
Poor prognosis: 50% of patients are wheelchair-bound after 5 years, with a median survival of 8 to 10 years
Ultrasound
Sole utility: detection of a distended bladder or post-void residual in patients with cerebellar or parkinsonian syndrome, for early screening of dysautonomia.
MRI
Brain:
- Putaminal, pontine, and middle cerebellar peduncle atrophy - T2 hypointensity of the posterior putamen, sometimes associated with a unilateral or bilateral T2 hyperintense rim along the posterolateral putaminal border
- "Hot cross bun" pontine T2 hyperintensity
- Flocculent T2 hyperintensities of the middle cerebellar peduncles
Note: T2* sequences appear to detect the putaminal hypointensity related to iron deposition at an earlier stage
Nuclear medicine
FDG-PET may demonstrate hypometabolism of the brainstem or striatum.
In a patient with atypical parkinsonian syndrome without cerebellar signs, PET demonstration of cerebellar hypometabolism may help establish the diagnosis.
Likewise, in a patient with cerebellar syndrome without parkinsonism, demonstration of nigrostriatal dopaminergic denervation by functional imaging (PET or SPECT) may support the diagnosis of MSA
Classification
2 subtypes:
- MSA-P, in which parkinsonism predominates,
- MSA-C, in which cerebellar syndrome predominates.